1. Field of the Invention
The present invention relates to a method of determining or recognizing the configuration of a path for motor vehicles through image processing, and more particularly to a method of recognizing boundaries of a path irrespective of the configuration of the path.
2. Prior Art
Recognition of the configuration of a path for motor vehicles requires that boundaries of the path at an end thereof be determined. To determine the boundaries of a path at an end thereof, it is necessary to process image data of the path at the end thereof, which are produced by a television camera or the like, and to extract line segments from the processed image data at the end of the path. One image processing method employs the Hough transformation as disclosed in Japanese Laid-Open Patent Publications Nos. 62(1987)-24310 and 62-70916. According to the disclosed process, feature points on an image produced by the image data are subjected to the Hough transformation, thereby producing a group of straight lines corresponding to the distribution of the feature points.
If the path to be recognized is straight, then the above conventional method based on the image processing can directly utilize the detected straight lines produced by way of the Hough transformation. If the path is curved or branched, however, the detected straight lines produced by way of the Hough transformation cannot be utilized as they are. In such a case, it has been customary to divide an image produced by a television camera into a plurality of small processing areas, and repeatedly detect line segments in the processing areas successively from a closest small area in the image, so that information accurately representing the boundaries of an actual path can be obtained.
With the conventional method, therefore, sequential steps are required to determine the configuration of a path, and the overall process is time-consuming. Accordingly, it has been difficult to apply the conventional method to the control of running of an automobile along paths since the automobile running control or guidance process requires quick data processing.